If radioactive plumes are released outside due to loss of containment building integrity during a nuclear power plant accident, these materials might travel with the wind, affecting both the surrounding environment and neighboring countries. In China, most nuclear power plants are located on the eastern coast. Consequently, a radioactive plume generated during an accident could negatively impact even the western part of the Korean Peninsula due to westerly winds. To detect such problems early, respond quickly, and protect residents, a system that can monitor aerial radiation under normal conditions is needed. Additionally, a detection system that can operate in real-time in an emergencies conditions is required. The current method for aerial radiation measurement takes environmental radiation data from a monitoring post 1.5 m above the ground and converts it to altitude. To measure actual aerial radiation, an expansive area is surveyed by aircraft. However, this approach is both time-consuming and expensive. Thus, to monitor radioactive plumes influenced by environmental factors like wind, we need a radiation detector that can gauge both radioactivity and directionality. In this study, we developed a radiation detector capable of assessing both the radioactivity and directionality of a radioactive plume and conducted its performance evaluation. We miniaturized the radiation detector using a CZT (Cadmium Zinc Telluride) sensor, enabling its mounting on unmanned aerial vehicles like drones. It is configured with multi-channels to measure directionality of a radioactive plumes. For performance evaluation, we positioned two-channel CZT sensors at 90 degrees and measured the energy spectrum for angle and distance using a disk-type radioactive isotope. Using this method, we compared and analyzed the directionality performance of the multi-channel radiation detector. We also confirmed its capability to discern specific radioactivity information and nuclide types in actual radioactive plumes. Our future research direction involves mounting the multi-channel radiation detector on a drone. We aim to gather actual aerial radiation data from sensors positioned in various directions.

Republic of Korea (ROK) is operating the Integrated Environmental Radiation Monitoring Network (IERNet) in preparation for a radioactive emergency based on Article 105 of the Nuclear Safety Act (Monitoring of Nationwide Radioactive Environment). 215 radiation monitoring posts are monitoring a wide area, but their location is fixed, so they can’t cover areas where the post is not equipped around the Nuclear Power Plants (NPPs). For this, a mobile radiation monitoring system was developed using a drone or vehicle. However, there are disadvantages: it is performed only at a specific cycle, and an additional workforce is required. In this study, a radiation monitoring system using public transportation was developed to solve the above problems. Considering the range of dose rates from environmental radiation to high radiation doses in accidents, the detector was designed by combining NaI (TI) (in the low-dose area) and GM detector (in the high-dose area). Field test was conducted by installed on a city bus operated by Yeonggwang-gun to confirm the performance of the radiation monitoring system. As a result of the field test, it was confirmed that data is transmitted from the module to the server program in both directions. Based on this study, it will be possible to improve the radiation monitoring capability near nuclear facilities.

Once a radioactive material is released from the nuclear power plant (NPP) by accident, it is necessary to understand the behavior of radioactive plume to protect residents adequately. For this, it is essential to measure the radiation dose rate around NPPs at important locations. Our previous study developed a movable radiation detector that can be installed quickly in an accident to measure gamma dose rate in areas where environmental radiation monitoring system is not installed. The data measured by the detector are transmitted to the server in real-time through LoRA wireless communications. There are two methods to use LoRA communications; one is self-network, and the other is the network provided by the mobile carrier. A signal receiver, called a gateway, should be equipped near the installation location of radiation detectors to use a self-network without using the mobile carrier’s system. In other words, the movable radiation detectors we made can function if there should be any gateway near them. The distance capable of communication between gateway and detector is about 8 km in an open area without significant obstacles. Korea has many significant obstacles, such as mountains around most NPPs. Thus, the gateways could be installed in the proper position before the accident to operate the movable radiation detectors without problems. If the gateway is located at a high position like a mountain top, it could cover a wide area. In this study, the elevation database in the area around the NPPs was collected and analyzed to determine where gateways should be installed. The analysis range is limited in the urgent protective action planning zone. The optimization was also performed to minimize the number of gateways.

본 논문에서는 고리 1호기 해체 비용 추정을 위해 외국 원자력발전소 해체 비용 데이터를 현가화한 후 원자력발전소 해체 비용 추정 회귀 분석모델을 개발하였다. 이 모델 개발에 사용된 데이터는 해체 또는 진행 중인 BWR 13기, PWR 16기의 해체 비용 데이터이다. 회귀 분석모델 도출을 위해, 해체 비용을 종속변수로 정하고, 해체 원전의 운전 특성을 반영할 수 있게 고 안된 Contamination factor와 해체 기간을 독립변수로 선정하였다. 빅데이터 분석 도구인 R language의 통계패키지를 이용 하여 회귀 분석모델을 도출하였다. 이 회귀 분석 모델을 적용하여 고리 1호기 해체 비용을 예측한 결과, 미화 663.40~928.32 백만 달러, 한화 약 7,828.12억~1조 954.18억 원이 소요될 것으로 예측되었다.

This study examines the determinants of the member customer’s decision of redeeming versus accumulating loyalty program (LP) points by focusing on the effects of the different channels of transaction (online versus offline) and the demographic information of member customers. Our study is based on customer-level demographic and transaction data on a major partnership LP in Korea, the OK Cashbag (OCB) program. This study differs from the existing literature in three aspects. First, the dataset employed for this study enables us to compare member customers’ point redemption behavior between online and offline channels, whereas previous studies demonstrate coupon redemption behavior either in an online (Chiou-Wei and Inman 2008) or an offline setting (e.g., Cronovich 1997; Kwon and Kwon 2007; Mittal 1994; Reibstein and Traver 1982; Ward and Davis 1978). Second, the current study investigates not only the main effects of demographic variables, but also a series of interaction effects between the online channel and each demographic variable. Clear empirical evidence of an interaction effect would provide an LP provider with significant managerial implications. Third, rich data on customers’ transaction behavior with matching demographic information for each member customer enable us to conduct both transaction-level and individual customer-level analyses. Therefore, an individual customer’s transaction behavior can be analyzed in more detail for robust results and richer implications. We find that transactions that occur through online channels and those made by younger customers demonstrate a greater tendency of redeeming LP points as opposed to accumulating them. We also find that online channels exhibit a moderating role by mitigating the demographic effects on member customers’ point redemption behavior. These findings allow the LP provider to predict the future LP point balance by analyzing its main channel of transaction and the demographic profiles of its member customers.

A new cultivar of Rosa hybrida “Orange Flash” was selected from the progenies of a cross between “Lora” and “Timeless” at the Gyeonggi-Do Agricultural Research and Extension Services in 2000. It was finally selected in 2004 after investigation of the characteristics for three years (2002-2004). “Orange Flash” was developed for a standard type cut flower. The major characteristics of “Orange Flash” are 107stems/m2/year in yield, 24.8 in petal number and 10.9 days in vase life. The cultivar was applied for a variety protection in 2005, and was released to commercial growers in 2006.

A new cultivar of Rosa hybrida “Pink Flash” was selected from the progenies of a cross between “Red Sandra” and “Neon” at the Gyeonggi-Do Agricultural Research and Extension Services in 2000. It was finally selected in 2004 after investigation of the characteristics for three years (2002-2004). “Pink Flash” was developed for a standard cut flower. The major characteristics of “Pink Flash” are 132stems/m2/year in yield, 57.7 in petal number and 8.0 days in vase life. The cultivar was applied for a variety protection in 2005 and was released to commercial growers in 2006.